Smoke damper



Patented Feb. 22,1927.

um; :s or Banam- Uma/ann mmsronnn, or 13mm; Gamm?.

SHORE DAHPEB..

Appnauon 1aed Apru 1s, 192s, serial ab. 101,760, ma 1a cermnyapru as, ma

order .that the stack draft maybe a le to,`

suck in atmospheric air directly instead o f from. the heated flueslofthe boiler. Since however withA the known construction this air inlet'passage has an immediate communication with the boiler and its lues itwas unavoidable that on account of the buoyancy 2o of the hot air withinthe boiler atmo heric cold vairv wasA4 also sucked through t e air inletpassage into the hot boiler, whereby the purpose of the arrangement waspractically' rendered illusory.

In order to do away with thisdraw-back we provide accordin to thisvpresent inyvention within'. the

:boiler tothe vstack and by means -of a sec- -ond additional damper avspecial' se arate space or compartment between the rboiler andthe stack,which space or compartment has a leakage connection with the stack andisladapted to communicate with the outer atmosphere, care being taken,that no bypass communication, such as for example a Adirect leakageconnection past the dampers and at the exclusion of `a said spaceorcompartment, may exist between the stack and l the boiler sides of thesmoke `lue. As av result of such arrangement-a pressure equal orsubstantially equal to atmospheric pres- 'surc is produced between thesmoke dampers constituting the said space or compartment, whereby anescape of heat from the boiler furnace or the like is successfullyprevented, as will be described more in detail hereinafter. i 'Inthedrawings illustrating some embodiments vof our inventionv l Fig. 1illustrates the general arrange- Fig. 3 is a Stnal view of amodiiication ue leading from the ment according tof our invention inconnec.

of the compound dxmper taken along 4line C-D Fig.5, v .'1'

.,Fig. 4 is a vertical cross section along line E-F Fig. 3,

- Fig. 5 1s a plan view of vthe modication 60 3, partly in section alongline A-B 1g.'3. According to Fig. 1 of thedrawing'the combustion gasesofbboiler 1 pass as usual through a lue 2 .to the `stack 3, a shutting-65 olf member, in this'particular instance, an ordinary smoke damper 4,being arranged within flue 2 between the boiler and the stack. Between'the damper 4 and the stack 3 We arrange according to our present inven-70 tion a secondslide` or damper 5 thus permitting to :shut-oilorseparate from flue 2 a closedv separate' space or compartment 6,

`when both slides or dampers 4, 5 are in their lowered or operativeposition as shown in Fig. 1.A The space or compartment 6 is adapted tocommunicate with the outer atmosphere by .means of an orifice or passage19 being controlledby an air inlet or valve mechanism 7. This'me'chanismcomprises a 80 seating member 8 having a peripheralgroove A or channel 9adaptedto receive a dlp-bell or valve member 10. The channel 9 is filledwithloos'e dry sand or fine-grained lead'- shot, the inner edge 11 ofmember 10 being 85 so bevelled as to urge the sand or the like towardsthe inner face of channel 9. Thev bell 10'is guided by a'bracket 12(Fig. 2) and attached to a Vcable 14 passing over sheaves 13 and havingat its end a counter- 90 weight 15 with which a tappet 16 is adaptedtoengage. This tappet -16 is attached to the rope or -cable 17 .carryingthe shde or damper 5- and having at its outer end a counter-weight 18,as show n. The tappet 16 is so attached to cable 17 thatit enga esweight 15 only and thereby lifts the va ve member Yfrom its seat, whenthe damper 5 is nearly closed. vAir is thus automatically admitted tothe s ace or compartment 6 100 whenever the two ampers are moved lntotheir lowered or o erative position. i Y

` In order' that t e operation of ourimproved damper arrangement-sc fardescrlbed may be readily understood 1t should be 105 borne in mind thatthe two slides or dempers 4 and 5 are moving in their guldes with acertain amount o unavoidable leakage. If

both dampers 4 and 5.are in their o rative 4position as shown in Fig. 1the 3 has 110 communication withthe space 6`through the leakage ofdamper 5 so that it can suck i 0H cold atmospheric air entering throughpassage 19. The stack 3 has however no 5 direct/leakage or by-passconnection at the exclusion of or around the space 6 with that part ofHue 2 which is located between the slide or damper 4 and the boiler l sothat I no heat can be carried 0H past such by-pass l0 l5 from space 6and throughthe leakage be-n tween damper 4 and its guide into the boiler1, so thatthe samewill retain substantially all of'the heat stored up inait, with the u only exception of the slight 'heat losses by 1 radiation2during the stand-still periods. Practical tests lhave shown that thetotal loss of heat occurring between two running periods can thus beconsiderablyreduced. In` many instances `the available space does damper5 at such a distance from damper f4 that thev air inlet mechanism showniny Fi s. 1 and 2 can be arranged betweenboth Vsli es or dampers. Alsothe operating mechanism for the air inlet device may be annoying sinceit will frequently have to be arranged in the passages of the boilerhouse. In-order to do away with this inconvenience and to facilitate themounting of the installation we yconstruct accordingto Figs. 3, 4 and 5a multiple, or compound Cdamper mechanism having a plurality of guidingledges, so that one guide or pair of guides pertains to one damper orslide respectively. This compound damper mechanism is guided forvertical movementin a damper guiding frame interposed in the Hue betweenthe boiler or furnace and stack and again constitutes a separate spaceor compartment adapted to communicate withfthe outer atin osphere bymeans of an air inlet mechamsm, when being in its lowered or operativepos1tion,.care being `again taken that ino Aleakage by-passcommunication can exist be'- ,tweenlthe stack side andthe boiler sideyofHue 2 around the space or compartment between the two slides or dampers.

f The ,arrangement of two groups of guiding ledges, one group for eachsllde member 0,5. grooves or Channels 2l and 22 wpemting not permit toarrange the second slide ,or'

lor damper, is therefore of importance, since i (Fig. 4). The'two plates26, 27 and their 70 connecting members 23 are thus constituting as aunitary self-contained structure a compound hollow smoke damper being atits upper end closed by Haps 29. In the lowered position of thiscompound damperEiFig.

3) the Haps are automatically opene by pushrods 30 loosely lsliding inbearings 31,

whereby atmospheric air is admitted to the hollow space. between the twoplates 26 and 27 and can slowly be sucked 0H' to the stack 80 throughvthe leakage between the guiding ledges `of the stack-adjacent damperplate and its guiding channels of frame 20, the.s operation being'thusexactly the same as that of the embodiment Figs. 1 and 2 at 85 whichboth Slides or dampers may be independently operated. Upon the damperbe-"ing lifted bv means off'lifting rod 32 and a suitable kind of hoistingmechanism the rods 30 will slide down and permit the Haps 29 90 toclose.

-The compound damper as such must of course be well calked against theouter air. To this end the lframef20 `is at its upper end providedwith/two transverse pocket-shaped beams 33 supporting rollers 34 'whichby their gravity always contact with the plates 26 and 27, whereby thegap is bridged which must always exist between the lmasonwork or the4damperA frame 20 and 100 the damper. The members 23 mustfhow-` ever alsobe calked against 'the outer air between the guiding ledges 24 and 25 inorder to prevent an air entrance into Hue 2 while the boiler and thestack are in their 105 normal operation. Wve therefore provide in themembers 23 channels35 adapted to receive one roller 36 respectivelycarried in chambers 37 of the damper guiding frame 20 and which are byJgravity always held lin airtight contact with the members`23,

lugs 38' being provided on the guiding frame 20 'and extending into thechannels 35 for the support of the rollers 36. In

order that the objectionable direct or bypass connection (between thestack side and the boiler side'of the Hue may be avoided we provide acommunication of the space between the damper plates 426, 27, the crosswall 39 of the gn e walls of frame 20 with the space between the damperplates 26 a'11d27 and the cross tall 39 by arranging air passages 40 inthe lower ends of the vwalls 39. Accordingly the stack draft can againnot act past the ledges 24 which may for example be on the' VboilerVsideof Hue 2 on the air within the boiler side of Hue 2 and within theboiler Hues.

By the arrangement of the vspace or colic- 13 embers\23 and the cross120 CFI partment adapted to communicate by leakage with the stack and tocommunicate by a valve mechanism with the outer air the stack draft canonly suck oft air from this space or compartment through thesufiiciently large air inlet orifice and there always eX- ists withinthis space or compartment a slight vacuum which is a little belowatmospheric pressure.` Accordingly and in the absence of any direct orby-pass leakage connection between the stack side and the boiler side ofthe fine' around the space or compartment no heat can be carried off byflowing air from the boiler lues into the stack; what will be dischargedmay eventually be the small gas quantities resulting from the belatedburningr down of some suspended fine coke particles.

What we claim as our invention is:

1. A smoke damper apparatus for interrupting 'the smoke fluecommunication between a stack andl a fire place comprising a smoke flue,a plurality of flue obstructing slides adapted to establish in the smokeflue a separate compartment so that any by-pass communication betweenthel stack and thcl tire placeand at the excluli'lliof the saidcompartment is prevented, and means for admitting air into the saidcompartment.

2. A smoke damper apparatus for interrupting the smoke {luecommunication between a stack and a lire lace comprising a smoke flue, aplurality F movable dainpers adapted to establish, when in Vtheir oneoperative positionin the smoke flue, a separate compartmenthavingleakage communication with the stack side and with the tire placeside of the smoke .flue at the exclusion of any direct leakageconnection between both smoke flue sides past the said compartment, andautomatic means for admitting air into the said compartment when. thedampers are in their compartment establishing positions.

3. A compound dam er comprising a pair of rigidly connecte (distanceddamper plates movable into and out of operative positioi,guiding meanstherefor adapted to Y constitute part of a smokeflue and permittingleakageconnection of the space intermediate t-he damper plates-with theadjoining ilue portions while preventing any direct connection of thesaid flue ortions at the exclusion of such interme iate space and meansfor admitting air into the space intermediate the damper plates.

A com ound dam er comprising a pair of rigi y c onnect distanced damperplates movabe into and ,out of operative position and adapted toseparate from a smoke flue a closed compartment when being in the oneoperative position, a guiding frame having lateral walls ada )ted to bein substantial alignment with adyoiningwalls 'of a smoke flue andpermitting in their cooperationwith the damper plates aleakageconnection of the space intermediate the damper plates with/the outsideof the saidl plates and at the exclusion of any direct bypass connectionof t-he said outsides past the said intermediate space, covers closingthe space between the two damper plates and means for,` automaticallyopening the said covers and for admitting air into the said intermediatespace when the two damper plates are in their operative position.

5. A compound Vdamper comprising a pair of rigidly connected distanceddamper plates movable between an operative and an inoperative position,aA guiding frame adapted tov constitute part of'a smoke flue and soceo-operating with the lsaid damper plate that a leakage connection ofyflue ends adjoining the guiding frame with the space intermediate thesaid damper plates is permitted while any direct byfpass connection cfthe adjoining 'flue endsat the exclusion of sucli intermediate space isprevented, covers closing the space .intermediate the said damper platesand automatic means adapted to lift the cover plates and admit air intothe said intermediate space, when the damper plates are in theiroperative position and to elose'the cover plates and cut out the airadmission, when the damper plates arexbeing moved' into theirinoperative position.

6. A-compound damper plate comprising a pair of rigidly connecteddistanced damper plates, a guiding frame therefor `adapted' to provideleaka e connection between the space interm iate the said plates and theand its guiding means and means for establishing a. permanentcommunication between the space 'intermediate the damper plates and thespaces intermediate the transverse walls and the guiding frame.

vspace outside the said guide and damper plates, transverse walls forconnecting the. said damper plates and being arranged at` In testimonywhereof we affix our signatures.

FELIX BAENTSCH. ALFRED sToBER.

